M 17-4 SETION - I (40 marks) ompulsory : Attempt all questions from this section. Question 1. (a) hoose the corresponding letter for the correct answer from the choices A,, and D. On moving from left to right in a period, the metallic character of elements A) increases ) decreases ) remains the same D) varies irregularly Which of the following contains maximum number of molecules? A) 4g of O 2 ) 4g of N 3 [10] (vi) (vii) (viii) (ix) (x) ) 4g of SO 2 ) 4g of O 2 The ions present at the anode during electrolysis of molten lead bromide are A) Pb 2+ ) r 2- ions ) r - ions D) none of these Which of the following has double bond between two atoms? A) 2 ) O 2 ) N 2 D) P 3 The equation for the reaction between magnesium and dilute sulphuric acid is shown. Mg + 2 SO 4 MgSO 4 + 2 Mol. wt of MgSO 4 is 120g. Which mass of magnesium sulphate will be formed if 12 g of magnesium is reacted with sulphuric acid. A) 5g ) 10g ) 60g D) 50g Which property is shown by all metals? A) They are extracted from their ores by heating with carbon. ) They conduct electricity. ) They form acidic oxides. D) They react with hydrochloric acid to form hydrogen. Which of the following is an unsaturated compound? A) 6 14 ) 3 7 O ) 3 O D) 4 8 A salt which in solution gives a bluish white precipitate with NaO solution and a white precipitate with al 2 solution is A) uso 4 ) FeSO 4 ) Fe 2 (SO 4 ) 3 D) ul 2 The gas law which relates the volume of a gas to moles of the gas is A) Avogadro s law ) Gay-Lussac s law ) oyle s law D) harle s Law Formation of chloroform from methane and chlorine is an example of A) Addition ) Dehydration ) Substitution D) Elimination M 17-4 237
X - ISE (hemistry) MT EDUARE LTD. (b) A gas cylinder contains 24 10 24 molecules of nitrogen gas. If the Avogadro s number is 6 10 23 and the relative atomic mass of nitrogen is 14, calculate A) Mass of nitrogen gas in the cylinder. ) Volume of nitrogen at STP. 3000 cc of oxygen was burnt with 600 cc. of ethane ( 2 6 ). alculate the volume of A) arbon dioxide formed ) Unused oxygen Name the following: A gas evolved when a white crystalline solid is warmed with a(o) 2 solution which turns moist litmus paper blue. A reagent that can distinguish between ethene and ethyne. A gas that can be oxidised to sulphur. The amount of substance containing particles equal to Avogardro s number. A complex salt used for electroplating an article with silver. (d) (e) State your observations for the following cases: onc. sulphuric acid is added to sugar. opper is heated with conc. nitric acid. Ammonia is burnt in oxygen. Lead carbonate is heated and then cooled. Potassium permanganate is heated with conc hydrochloric acid. Write equations for the following reactions: Excess ammonia reacts with chlorine. When sulphur reacts with conc. nitric acid. Lead (IV) oxide reacts with conc. hydrochloric acid. Nitrogen dioxide and water in presence of oxygen. Sodium thiosulphate reacts with dilute hydrochloric acid. (f) Write the I.U.P.A.. names of the following compounds. O O 3 2 5 O 2 5 (g) The following diagram illustrates electro refining of copper. Answer the following questions based on diagrammatic illustration. 238 M 17-4
MT EDUARE LTD. attery X - ISE (hemistry) u2+ u2+ What is the cathode made up of? Which is the electrolyte used? Give the reaction occurring at the anode? Name any other two metals which can also be refined by this method. Slime is left during electro refining. What is this slime. Question 2. (a) SETION - II (Attempt any four questions) Study the diagram illustrating the manufacture of sulphuric acid given below. Give equations for following conversion identify A,, & D. SO 2 SO 3 [4] A FeS F sulphur Oleum E D (b) Nitric G 2 SO 4 acid From the metals copper, iron, magnesium, sodium and zinc, select a different metal in each case which : an form 2+ and 3+ ions. as a hydroxide that reacts with both acids and alkalis. does not react with cold water but reacts with steam reversibly when heated. hoosing only substances from the list given in the box below, write equations for the reactions which you would use in the laboratory to obtain: Sodium sulphate Iron (II) sulphate Zinc carbonate Dilute sulphuric acid Iron opper carbonate Sodium Sodium carbonate Zinc Question 3. (a) Element Atomic number A Z 1 Z + 1 D Z 1 In the table given above A,, and D are elements. Given is an inert gas (not helium), what type of bonding would take place between A and A and D M 17-4 Z 239
X - ISE (hemistry) MT EDUARE LTD. (b) State the anion present in each of the following solutions A,, and D. An aqueous solution of A on heating with dilute mineral acid, give a gas which turns lead acetate paper silvery black. An aqueous solution of reacts with barium nitrate solution to give a white precipitate insoluble in dil. nitric acid. The solution reacts with con. sulphuric acid on heating to give acid vapours which on heating with copper turnings gives a gas which turns potassium iodide solution brown. The substance D reacts with dilute sulphuric acid on heating to a colourless,odourless gas which turns lime water milky. [4] (d) From the list of the substances given below: Washing soda, Ferric chloride, Sodium chloride ydrogen chloride. Name the compound which would: Gains weight on exposure to air. Loses weight on exposure to air. Draw the electron dot diagram of a molecule of arbon tetrachloride Water Question 4. (a) Write the equations for the following laboratory preparations: Ethane from sodium propionate Ethene from iodoethane Ethene from ethyl alcohol Ethyne from calcium carbide Ethanoic acid from ethanal (b) Draw the structural formula of the final product when ethane reacts with excess chlorine in the presence of diffused sunlight. What would you observe when ethyne is passed through ammoniacal silver nitrate solution? X and Y are successive members of the same homologous series. If the molecular mass of X is 60, what is the molecular mass of Y. What is glacial acetic acid? Define catenation. Question 5. (a) This question is based on laboratory preparation of ydrogen chloride gas. See the diagram below and answer the following question. A D Write the chemicals A and used in the reaction. 240 M 17-4
MT EDUARE LTD. X - ISE (hemistry) (b) Write the balanced chemical equation for the reaction taking place in the above process. What happes when the glass rod dipped in ammonia is brought near the mouth of jar. What is the use of conc. sulphuric acid in D. Why Nitric acid is not used in preparation of ydrogen chloride. From the equation (N 4 ) 2 r 2 O 7 r 2 O 3 + 4 2 O + N 2 alculate the Volume of nitrogen at STP evolved when 63 g of ammonium dichromate is heated. Mass of chromium (III) oxide formed at the same time. (N = 14, = 1, r = 52, O = 16) A gaseous hydrocarbon contains 82.6% carbon. If the vapour density of hydrocarbon is 29, calculate its molecular formula. ( = 12, =1) Question 6. (a) Name the following : a non-metal which is in liquid state. a non-metal which is lustrous and sublimes on heating. a metal which is a poor conductor of electricity. method used to concentrate sulphide ores. a non-metal which is ductile. (b) Write a balanced equations for : The reaction of magnesium nitride with warm water. The reaction of dilute nitric acid with zinc. Account for the yellow colour that appears when conc.nitric acid is left standing in an ordinary glass bottle. Give the name and formula of the brown - ring formed in the test for nitrates. Nitric acid is used in etching glass and metalware. Explain why? Question 7. (a) Given P -11, Q-13, R-15, S-17 are four atoms of different elements. Which of the four atoms are metals. Which of the metals mentioned in would be most metallic in nature. Arrange the above elements in decreasing order of the electronegativity. Name the inert gas of the period. Write the formula of the ion formed by R-15. (b) State whether the underlined element has undergone oxidation or reduction in the equations given below. l 2 + 2 S 2l + S Zn + uso 4 ZnSO 4 + u 2KI + 2 O 2 I 2 + 2KO Show the formation of ammonium ion. M 17-4 241